1. Field of the Invention
The present invention relates to nautical lights for navigational purposes. Some nautical navigation lights are detachable from the base, which for boat applications allows the lights to be stored out of the way, an advantage for many daytime activities and boat storage. Other nautical navigation lights are fixed to the base. Nautical navigation lights may be a single color, such as typically used for boat stern lights and navigation buoys, or two colors such as used in some boat bow lights and some bridge structures. For boat stern lights and navigation buoys, a single color is visible for typically all directions. For the case of boat bow lights and some bridge structures, one color of light is visible from one direction and another color light is visible from an opposing direction. The two color lights may be two discrete light sources located on opposing sides or one two color bifurcated source. Some nautical navigation lights flash at a predetermined rate. Buoys are one example where flashing lights are common.
2. Background Art
Detachable nautical navigation lights typically consist of a base which is mounted to a structure and a pole which mechanically couples to the base. The pole has a light emitting device (typically an incandescent bulb) at the distal end. Power to energize the bulb is coupled via electrical contacts at the base and at the bulb socket at the distal end of the pole. Fixed in place nautical navigation lights have a similar construction with typically shorter poles and without the base electrical contacts.
Electrical contacts are composed primarily of copper and copper alloys. Although weather covers are typically provided to cover the electrical contacts, water intrusion almost always occurs. Copper electrical contacts exposed to moisture leads to corrosion and eventual electrical failure of the contacts. The problem is particularly acute in marine environments.
Several US patents describe prior art systems which are related but differ from the invention.
U.S. Pat. No. 4,389,085 to Mori describes a fiber optic system which collects and distributes sunlight.
U.S. Pat. No. 4,740,870 to Moore discloses a central light source which is transmitted to different areas of a boat via fiber optic cabling.
U.S. Pat. No. 5,161,874 to Benes describes a remote illumination system that utilizes a single light source and a light pipe to transmit the light to some remote locations from the source.
U.S. Pat. No. 5,339,225 to Wiggerman is a boat stern light design that illuminates the length of the pole, as opposed to just having a light at the distal end.
U.S. Pat. No. 6,155,195 to Nirenberg discloses a telescoping stern light that can be retracted out of the way when not in use.
U.S. Pat. No. 6,742,916 B1 to Dunn describes a fiber optic cabling system for the sides of boats which is intended illuminate said side for safety or enjoyment purposes.